def split(filename, nlines, prefix, suffix)
	n = 0
	i = 1
	file = nil
	IO.foreach(filename) do |line|
		if n % nlines == 0
			file.close() if not file.nil?
			file = File.new(prefix + i.to_s() + suffix, "w+")
			i += 1
		end
		n += 1
		file.puts(line)
	end
	file.close() if not file.nil?
end

